crctab = [
    0x00000000,
    0x04C11DB7,
    0x09823B6E,
    0x0D4326D9,
    0x130476DC,
    0x17C56B6B,
    0x1A864DB2,
    0x1E475005,
    0x2608EDB8,
    0x22C9F00F,
    0x2F8AD6D6,
    0x2B4BCB61,
    0x350C9B64,
    0x31CD86D3,
    0x3C8EA00A,
    0x384FBDBD,
    0x4C11DB70,
    0x48D0C6C7,
    0x4593E01E,
    0x4152FDA9,
    0x5F15ADAC,
    0x5BD4B01B,
    0x569796C2,
    0x52568B75,
    0x6A1936C8,
    0x6ED82B7F,
    0x639B0DA6,
    0x675A1011,
    0x791D4014,
    0x7DDC5DA3,
    0x709F7B7A,
    0x745E66CD,
    0x9823B6E0,
    0x9CE2AB57,
    0x91A18D8E,
    0x95609039,
    0x8B27C03C,
    0x8FE6DD8B,
    0x82A5FB52,
    0x8664E6E5,
    0xBE2B5B58,
    0xBAEA46EF,
    0xB7A96036,
    0xB3687D81,
    0xAD2F2D84,
    0xA9EE3033,
    0xA4AD16EA,
    0xA06C0B5D,
    0xD4326D90,
    0xD0F37027,
    0xDDB056FE,
    0xD9714B49,
    0xC7361B4C,
    0xC3F706FB,
    0xCEB42022,
    0xCA753D95,
    0xF23A8028,
    0xF6FB9D9F,
    0xFBB8BB46,
    0xFF79A6F1,
    0xE13EF6F4,
    0xE5FFEB43,
    0xE8BCCD9A,
    0xEC7DD02D,
    0x34867077,
    0x30476DC0,
    0x3D044B19,
    0x39C556AE,
    0x278206AB,
    0x23431B1C,
    0x2E003DC5,
    0x2AC12072,
    0x128E9DCF,
    0x164F8078,
    0x1B0CA6A1,
    0x1FCDBB16,
    0x018AEB13,
    0x054BF6A4,
    0x0808D07D,
    0x0CC9CDCA,
    0x7897AB07,
    0x7C56B6B0,
    0x71159069,
    0x75D48DDE,
    0x6B93DDDB,
    0x6F52C06C,
    0x6211E6B5,
    0x66D0FB02,
    0x5E9F46BF,
    0x5A5E5B08,
    0x571D7DD1,
    0x53DC6066,
    0x4D9B3063,
    0x495A2DD4,
    0x44190B0D,
    0x40D816BA,
    0xACA5C697,
    0xA864DB20,
    0xA527FDF9,
    0xA1E6E04E,
    0xBFA1B04B,
    0xBB60ADFC,
    0xB6238B25,
    0xB2E29692,
    0x8AAD2B2F,
    0x8E6C3698,
    0x832F1041,
    0x87EE0DF6,
    0x99A95DF3,
    0x9D684044,
    0x902B669D,
    0x94EA7B2A,
    0xE0B41DE7,
    0xE4750050,
    0xE9362689,
    0xEDF73B3E,
    0xF3B06B3B,
    0xF771768C,
    0xFA325055,
    0xFEF34DE2,
    0xC6BCF05F,
    0xC27DEDE8,
    0xCF3ECB31,
    0xCBFFD686,
    0xD5B88683,
    0xD1799B34,
    0xDC3ABDED,
    0xD8FBA05A,
    0x690CE0EE,
    0x6DCDFD59,
    0x608EDB80,
    0x644FC637,
    0x7A089632,
    0x7EC98B85,
    0x738AAD5C,
    0x774BB0EB,
    0x4F040D56,
    0x4BC510E1,
    0x46863638,
    0x42472B8F,
    0x5C007B8A,
    0x58C1663D,
    0x558240E4,
    0x51435D53,
    0x251D3B9E,
    0x21DC2629,
    0x2C9F00F0,
    0x285E1D47,
    0x36194D42,
    0x32D850F5,
    0x3F9B762C,
    0x3B5A6B9B,
    0x0315D626,
    0x07D4CB91,
    0x0A97ED48,
    0x0E56F0FF,
    0x1011A0FA,
    0x14D0BD4D,
    0x19939B94,
    0x1D528623,
    0xF12F560E,
    0xF5EE4BB9,
    0xF8AD6D60,
    0xFC6C70D7,
    0xE22B20D2,
    0xE6EA3D65,
    0xEBA91BBC,
    0xEF68060B,
    0xD727BBB6,
    0xD3E6A601,
    0xDEA580D8,
    0xDA649D6F,
    0xC423CD6A,
    0xC0E2D0DD,
    0xCDA1F604,
    0xC960EBB3,
    0xBD3E8D7E,
    0xB9FF90C9,
    0xB4BCB610,
    0xB07DABA7,
    0xAE3AFBA2,
    0xAAFBE615,
    0xA7B8C0CC,
    0xA379DD7B,
    0x9B3660C6,
    0x9FF77D71,
    0x92B45BA8,
    0x9675461F,
    0x8832161A,
    0x8CF30BAD,
    0x81B02D74,
    0x857130C3,
    0x5D8A9099,
    0x594B8D2E,
    0x5408ABF7,
    0x50C9B640,
    0x4E8EE645,
    0x4A4FFBF2,
    0x470CDD2B,
    0x43CDC09C,
    0x7B827D21,
    0x7F436096,
    0x7200464F,
    0x76C15BF8,
    0x68860BFD,
    0x6C47164A,
    0x61043093,
    0x65C52D24,
    0x119B4BE9,
    0x155A565E,
    0x18197087,
    0x1CD86D30,
    0x029F3D35,
    0x065E2082,
    0x0B1D065B,
    0x0FDC1BEC,
    0x3793A651,
    0x3352BBE6,
    0x3E119D3F,
    0x3AD08088,
    0x2497D08D,
    0x2056CD3A,
    0x2D15EBE3,
    0x29D4F654,
    0xC5A92679,
    0xC1683BCE,
    0xCC2B1D17,
    0xC8EA00A0,
    0xD6AD50A5,
    0xD26C4D12,
    0xDF2F6BCB,
    0xDBEE767C,
    0xE3A1CBC1,
    0xE760D676,
    0xEA23F0AF,
    0xEEE2ED18,
    0xF0A5BD1D,
    0xF464A0AA,
    0xF9278673,
    0xFDE69BC4,
    0x89B8FD09,
    0x8D79E0BE,
    0x803AC667,
    0x84FBDBD0,
    0x9ABC8BD5,
    0x9E7D9662,
    0x933EB0BB,
    0x97FFAD0C,
    0xAFB010B1,
    0xAB710D06,
    0xA6322BDF,
    0xA2F33668,
    0xBCB4666D,
    0xB8757BDA,
    0xB5365D03,
    0xB1F740B4,
]


def crc_32_fast(msg):
    crc = 0x0
    for byte in msg:
        crc = ((crc << 8) & 0xFFFFFF00) ^ crctab[((crc >> 24) & 0xFF) ^ byte]
    crc = crc & 0xFFFFFFFF
    return crc


def crc32(data):
    poly = 0x4C11DB7
    crc = 0x00000000
    for byte in data:
        for bit in range(7, -1, -1):
            z32 = crc >> 31
            crc = crc << 1
            if ((byte >> bit) & 1) ^ z32:
                crc = crc ^ poly
            crc = crc & 0xFFFFFFFF
    return crc
